Signup to receive email updates




or follow our RSS feed

Blog Archives

316 Total Posts

follow our RSS feed

Blog Banner

Over the Fence

Where gardeners come to find out what's happening out in the yard.

Got White Pines, Spruce and Arborvitae?

Posted by Richard Hentschel -

Down the Garden Path

Richard Hentschel, Extension Educator

Extension offices are already getting calls about needle evergreens that are not looking healthy. If you drive your neighborhood right now you can spot those evergreens that died late last fall and those that are failing now. Arborvitaes are standing dead in many locations in the Fox Valley. Those that were planted in the last two years and especially in 2012 are the most susceptible to decline as a result of the 2012 drought. Others look ok right now but will decline as soon as warmer weather arrives.

Spruce are not well adapted to our area although they do grow pretty well for us.

Colorado blue spruce is an example. Colorado blue spruce have been planted for many years and often as the focal point in a landscape. While young, few problems are apparent. As they age it is typical for them to have some trouble with needle blights and Cytospora canker. With last summer's drought, spruces are going to be even more likely to contract these problems.

Besides the dead Arborvitae that we can see, there are pines that died last fall too. Two common pines that are planted are Austrian (Black) pine and White pine. Austrian pine are loved because they create those beautiful candles as the new growth expands each year and the White pines for their soft texture and with sound as the wind blows through them. Austrian pines have performed well in the landscapes being pretty adaptable, yet like spruce, are not really at home here. Austrian pines have had several needle diseases including diplodia tip blight and can have a combination of needle diseases at the same time. Just like the arborvitae, as temperatures rise, we can expect to see Austrian pine turn brown or just after they begin to grow, then turn. White pine being more native to Illinois fairs better, but is not without problems either. In a typical year, White pines tolerate needle diseases pretty well. White pines that are stressed from the 2012 drought will be more prone to needle disease development.

What the Plant Clinic on the campus of the University of Illinois and I suspect plant clinics from our neighboring states are seeing are the common needle diseases and those that are not normally a problem for our spruce and pine. This increase in disease incidence will make it that much harder for our needle evergreens to recover during 2013.

What is also on the rise is the secondary invasion of wood borers. These insects will be attracted to all kinds of woody plants, just not the evergreens. In fact in a lot of cases, the calls are about boring insects, not the needle diseases. The borers show up as a result of the trees being stressed and not the true cause of why the trees are failing.

Start this spring with the idea that our needle evergreens are stressed, that those needle diseases are present. Be sure those plants are well watered by nature or you and consider a light fertilization to help energize the plants. Plants generally have a lessor root system now than they did the spring of 2012. That also goes for the amount of food reserves for new growth in 2013.



Please share this article with your friends!
Share on Facebook Tweet on Twitter